(1) Field of the Invention
The present invention relates to laundry detergents or cleaning compositions which have, as a builder component, only water-soluble constituents and comprise soil release-capable cellulose derivative.
In addition to the surfactants which are indispensable for the washing and cleaning performance, laundry detergents and cleaning compositions also comprise what are known as builder substances which have the task of promoting the performance of the surfactants by attempting to eliminate hardness formers, i.e. substantially calcium and magnesium ions, out of the wash liquor in such a way that they do not interact adversely with the surfactants. Polyphosphates, in particular trisodium polyphosphate were formerly used very successfully for this purpose. A further known example of such builder substances which improve the primary washing action is zeolite Na-A, which is known to be capable of forming such stable complexes with calcium ions in particular that their reaction with water hardness-forming anions, in particular carbonate, to form insoluble compounds is suppressed. In addition, the builders, especially in textile laundry detergents, are intended to prevent the reattachment of the soil released from the fiber or generally from the surface to be cleaned, and also insoluble compounds which form by the reaction of water hardness-forming cations with water hardness-forming anions on the cleaned textile or the surface. For this purpose, what are known as cobuilders, generally polymeric polycarboxylates, are typically used, which, in addition to their contribution to the secondary washing capacity, advantageously also have complexing action against the water hardness-forming cations.
In addition to the indispensable ingredients mentioned, such as surfactants and builder materials, laundry detergents generally comprise further constituents which can be summarized under the term washing assistants and which comprise such different active substance groups as foam regulators, graying inhibitors, bleaches, enzymes and dye transfer inhibitors. Such assistants also include substances which impart to the laundry fiber soil-repellent properties and which, if present during the washing operation, are capable of promoting the soil release capability of the remaining laundry detergent constituents. The same applies mutatis mutandis for cleaning compositions for hard surfaces. Such soil release-capable substances are often referred to as “soil release” active substances or, owing to their capability of modifying the treated surface, for example of the fiber, in a soil-repellent manner, as “soil repellents.” For example, the U.S. Pat. No. 4,136,038 discloses the soil release-capable action of methylcellulose. The European patent application EP 0 213 729 discloses the reduced redeposition in the case of use of laundry detergents which comprise a combination of soap and nonionic surfactant comprising alkylhydroxyalkylcellulose. The European patent application EP 0 213 730 discloses textile treatment compositions which comprise cationic surfactants and nonionic cellulose ethers having HLB values of from 3.1 to 3.8. The U.S. Pat. No. 4,000,093 discloses laundry detergents which comprise from 0.1% by weight to 3% by weight of alkylcellulose, hydroxyalkylcellulose or alkylhydroxyalkylcellulose, and also from 5% by weight to 50% by weight of surfactant, the surfactant component consisting substantially of C10- to C13-alkyl sulfate and having up to 5% by weight of C14-alkyl sulfate and fewer than 5% by weight of alkyl sulfate having alkyl radicals of C15 and higher. The U.S. Pat. No. 4,174,305 discloses laundry detergents which comprise from 0.1% by weight to 3% by weight of alkylcellulose, hydroxyalkylcellulose or alkylhydroxyalkylcellulose, and also from 5% by weight to 50% by weight of surfactant, the surfactant component consisting substantially of C10- to C12-alkylbenzenesulfonate and having fewer than 5% by weight of alkylbenzenesulfonate having alkyl radicals of C13 and higher. The European patent application EP 0 634 481 relates to a laundry detergent which comprises alkali metal percarbonate and one or more nonionic cellulose derivatives. Among the latter, explicitly disclosed are merely hydroxyethylcellulose, hydroxypropylcellulose and methylcellulose, and also, within the examples, the methylhydroxyethylcellulose Tylose® MH50, the hydroxypropylmethylcellulose Methocel® F4M and hydroxybutylmethylcellulose. The European patent EP 0 271 312 (P&G) relate to soil release-capable active substances, and among these cellulose alkyl ethers and cellulose hydroxylalkyl ethers (having DS from 1.5 to 2.7 and molar masses of from 2000 to 100 000) such as methylcellulose and ethylcellulose, which are to be used with peroxygen bleach in a weight ratio (based on the active oxygen content of the bleach) of from 10:1 to 1:10. The European patent EP 0 948 591 B1 discloses a laundry detergent in liquid or granular form which imparts to fabrics and textiles which are washed therewith textile appearance advantages such as pilling/fuzz reduction, counteraction of dye fading, improved attrition resistance and/or enhanced softness, and which contains from 1 to 80% by weight of surfactant, from 1 to 80% by weight of organic or inorganic builder, from 0.1 to 80% by weight of a hydrophobically modified nonionic cellulose ether having a molar mass of from 10 000 to 2 000 000, the modification consisting in the presence of optionally oligomerized (degree of oligomerization up to 20) ethyleneoxy or 2-propyleneoxy ether units and of C8-24-alkyl substituents, and the alkyl substituents having to be present in amounts of 0.1-5% by weight based on the cellulose ether material.
Owing to their chemical similarity to polyester fibers, particularly effective soil release-capable active ingredients in the case of textiles composed of this material are copolyesters which contain dicarboxylic acid units, alkylene glycol units and polyalkylene glycol units. Soil release-capable copolyesters of the type mentioned and also their use in laundry detergents have been known for some time.
For example, the German laid-open specification DT 16 17 141 describes a washing process using polyethylene terephthalate-polyoxyethylene glycol copolymers. The German laid-open specification DT 22 00 911 relates to laundry detergents which comprise nonionic surfactant and a copolymer composed of polyoxyethylene glycol and polyethylene terephthalate. The German laid-open specification DT 22 53 063 mentions acidic textile modifying compositions which comprise a copolymer composed of a dibasic carboxylic acid and an alkylene polyglycol or cycloalkylene polyglycol, and also optionally an alkylene glycol or cycloalkylene glycol. Polymers composed of ethylene terephthalate and polyethylene oxide terephthalate in which the polyethylene glycol units have molar masses of from 750 to 5000 and the molar ratio of ethylene terephthalate to polyethylene oxide terephthalate is from 50:50 to 90:10, and their use in laundry detergents are described in the German patent DE 28 57 292. Polymers having molar mass from 15 000 to 50 000 and composed of ethylene terephthalate and polyethylene oxide terephthalate, the polyethylene glycol units having molar masses of from 1000 to 10 000 and the molar ratio of ethylene terephthalate to polyethylene oxide terephthalate being from 2:1 to 6:1, can be used in laundry detergents according to the German laid-open specification DE 33 24 258. The European patent EP 066 944 relates to textile treatment compositions which comprise a copolyester composed of ethylene glycol, polyethylene glycol, aromatic dicarboxylic acid and sulfonated aromatic dicarboxylic acid in certain molar ratios. The European patent EP 185 427 discloses polyesters which are end group-capped by methyl or ethyl groups and have ethylene terephthalate and/or propylene terephthalate and polyethylene oxide terephthalate units, and laundry detergents which comprise such soil release polymers. The European patent EP 241 984 relates to a polyester which, in addition to oxyethylene groups and terephthalic acid units, also contains substituted ethylene units and glycerol units. The European patent EP 241 985 discloses polyesters which, in addition to oxyethylene groups and terephthalic acid units, contain 1,2-propylene, 1,2-butylene and/or 3-methoxy-1,2-propylene groups and also glycerol units, and are end group-capped with C1- to C4-alkyl groups. The European patent EP 253 567 relates to soil release polymers which have a molar mass of from 900 to 9000 and are composed of ethylene terephthalate and polyethylene oxide terephthalate, the polyethylene glycol units having molar masses of from 300 to 3000 and the molar ratio of ethylene terephthalate to polyethylene oxide terephthalate being from 0.6 to 0.95. The European patent application EP 272 033 discloses polyesters which are at least partly end group-capped by C1-4-alkyl or acyl radicals and have polypropylene terephthalate and polyoxyethylene terephthalate units. The European patent EP 274 907 describes terephthalate-containing soil release polyesters which are end group-capped by sulfoethyl. In the European patent application EP 357 280, soil release polyesters having terephthalate, alkylene glycol and poly-C2-4-glycol units are prepared by sulfonation of unsaturated end groups. The German patent application DE 26 55 551 describes the reaction of such polyesters with isocyanate-containing polymers and the use of the thus prepared polyesters against the reattachment of soil in the course of washing of synthetic fibers. The German patent application DE 28 46 984 discloses laundry detergents which comprise, as a soil release-capable polymer, a reaction product of a polyester with a prepolymer containing terminal isocyanate groups, obtained from a diisocyanate and a hydrophilic nonionic macrodiol.
The majority of the polymers known from this extensive prior art have the disadvantage that, in the case of textiles which do not consist, or at least do not consist predominantly, of polyester, they only have insufficient, if any, effectiveness. However, a large part of modern textiles consists of cotton or cotton-polyester mixed fabrics, so that there is a need for soil release-capable polymers having better activity in the case of greasy stains on such textiles.